Enhancement of luminescent properties of ZnS:Mn nanophosphors by controlled ZnO capping

Results of a method is presented for synthesizing ZnS:Mn nanoparticles capped in situ by ZnO. Analysis of Raman spectra and x-ray photoelectron spectra results have reinforced claim of the formation of ZnO capping layer on the surface of ZnS:Mn nanoparticles. Raman spectra results also showed presence of stress at an optimum ZnO capping thickness. In brief, the only variation within samples is in their ZnO capping thickness. Phase formation was analyzed and confirmed from powder x-ray diffraction. ZnS:Mn particle size is about 4 nm. The change in photoluminescent properties with ZnO capping thickness variation is presented. It is shown that the variation in ZnO thickness and the resultant stress leads to an enhanced photoluminescence intensity/efficiency of nano-ZnS:Mn. (C) 2004 American Institute of Physics.